The shipping industry uses large cargo containers to ship cargo from one location to another in domestic and global commerce. Such containers are designed to be conveniently moved from one mode of transport to another across the land by road or on rail or over the sea. Such containers are sometimes referred to as “intermodal shipping containers” or “freight containers.” The use of such containers has essentially eliminated the need for manually transferring cargo from one vessel to another, or from one vehicle or railcar to another in the effort to deliver the cargo to its final destination.
Today, cargo containers are generally standardized by internationally recognized standards, and by national domestic standards with respect to dimensions and structure. Thus, the standard containers can be securely arranged in vertical stacks in side-by-side and end-to-end relationship with each other, and can be handled most effectively when transferring from one mode of transport to another regardless of their source or destination.
Often, these containers must be transported empty from one delivery point to the next location where cargo is available for shipment. Transport of empty containers costs the shipper money and erodes profits since transport of each such container incurs handling cost and occupies valuable space which could otherwise be used to ship a revenue producing container loaded with cargo. Additionally, the shipping of both loaded and empty containers creates problems such as how to arrange the lighter, empty containers and the heavier, loaded containers aboard ships in such a manner that the safety of the ships is not compromised. Beyond safety issues, the shipment of empty containers causes monetary losses for shippers, losses which result in either substantial financial impact on the shipper or increased charges to customers for the handling and transport of loaded containers. Similar cost disadvantages apply when shipping empty containers over road or by rail.
Long ago shippers recognized that significant economic savings could be realized if empty containers could be “folded” so as to occupy a substantially smaller space when not in use, so that less space need be sacrificed in the transporting of empty containers. Such an effort presently exists only for the “open frame” or flat rack type containers. To that end, the prior art proposed many foldable or nesting cargo containers of the enclosed types intended to reduce the space required for their shipment when empty. While such prior art foldable containers have been proposed, the market has not embraced the prior art containers as a substitute for the standard, non-foldable cargo containers due to these prior art foldable containers not meeting ISO standards and ISO certifications for being water proof.
A shortcoming of foldable containers of the prior art, such as those depicted in FIGS. 1 and 2, is the lack of structural designs which enable or facilitate the folding and un-folding of such containers in a simple and effective manner with commonly available equipment. For example, prior mechanisms for securing container walls together required large amount of force applied to assemble or disassemble the mating components. Such configurations are disadvantageous due to the space constraints and force required.